1. Technical Field
The embodiment of the invention relates generally to managing use of lease resources allocated on fallover in a high availability computing environment.
2. Description of Related Art
In some computing environments, it is important that the computing environment continue to handle application workloads even if one or more resources handling the application workloads within the computing environment, fail. For a computing environment to continue to handle application workloads, even if one or more resources handling the application workloads within the computing environment fail, the computing environment may implement redundant computers in groups or clusters and implement a high availability controller that provides for automated continued service to application workloads when system components within the computing environment fail. In one example, application workloads require one or more applications running on one or more resources in a resource group. To provide high availability for applications needed for application workloads, when system components fail or other conditions in the cluster change, the high availability (HA) controller detects when the conditions in the cluster change, and moves the resource group for the workload to a standby node. Moving the resource group for the workload to a standby node includes configuring the resources required for the resource group on the standby node and starting the applications for the workload on the resource group on the standby node.
For an HA controller to start applications on a standby node, the HA controller determines whether the standby node needs additional processor, memory, and other hardware resources for the resource group to handle the applications and configures the resource group on the standby node with the required resources before starting the application on the standby node. In some computing environments, the HA controller can dynamically add physical and logical resources to a standby node, such as by dynamically allocating CPUs and memory to a logical partition on a node, to increase the hardware resources available for handling application workloads moved over to the standby node.
In some computing systems, the resources that can be dynamically allocated to a standby node include on demand, lease resources, such as IBM®'s Capacity Upgrade on Demand (CUoD) resources (IBM is a trademark of International Business Machines Corporation). CUoD resources are hardware resources that are preinstalled into a server to provide additional capacity, such as additional CPU and memory, but are not active until a client decides to enable the CUoD resources by acquiring a license to activate the CUoD resources, from a service provider, for a lease period for a fee. The high availability controller or a user determines when to activate lease resources, such as for increasing the resources available to a standby node to handle a fallover of an application for a workload from a primary node.